Link chain for chain conveyors and horizontal chain links therefor

Abstract

A link chain or a chain link for scraper chain conveyors with vertical and horizontal chain links which are interlinked in an articulated manner for scraper chain conveyors for use in mining. In particular to horizontal chain links with front sections with a straight face zone and with longitudinal limbs, which connect the front sections around an oval inner opening and which are provided on their outer surfaces with a recess, wherein the rear sides of front sections delimiting the inner opening form a contact zone for circular arcs of vertical chain links. In order to improve the service life of the link chain, the rear sides, which face oval inner opening, of front sections are provided with a surface which has a hollow, which forms a central region of the contact zone, between a fillet cambered in a crowned manner.

The invention claimed is: 
     
       1. A link chain for chain conveyors, in particular scraper chain conveyors for use in mining, comprising:
 vertical chain links which have around the full circumference a constant cross-sectional profile provided on the inside with a circular arc and on the outside with a flat section; 
 horizontal chain links which have front sections with a straight face zone and longitudinal limbs, which connect the front sections around an oval inner opening and which are provided on their outer surfaces with a recess; 
 wherein the rear sides of the front sections delimiting the inner opening form a contact zone for the circular arcs of the vertical chain links, the horizontal chain links are provided on the rear sides, which face the oval inner opening, of the front sections with a surface which has a hollow, which forms a central region of the contact zone, within a fillet cambered in a crowned manner; and 
 wherein the vertical chain links are provided at the transition of the flat section to the circular arc with a bevel, wherein the cross-sectional profile of the vertical chain links preferably has a width to thickness ratio L v /D v >2. 
 
     
     
       2. A link chain according to  claim 1 , wherein the hollow extends with a constant radius of curvature across the surface of the rear sides of the front sections. 
     
     
       3. A link chain according to  claim 2 , wherein the radius of curvature of the hollow has a crown line which lies on a central longitudinal plane between the longitudinal limbs of the horizontal chain links. 
     
     
       4. A link chain according to  claim 3 , wherein the front sections have in the central longitudinal plane a circular cross-section with a radius which is preferably of equal size or substantially of equal size to the radius of curvature of the crowned fillet. 
     
     
       5. A link chain according to  claim 3 , wherein the crown line of the hollow forms a semicircle around the centre point of the front sections in the central longitudinal plane. 
     
     
       6. A link chain according to  claim 3 , wherein the hollow on the rear side of the front sections comprises a rotationally symmetrical unwinding of the radius of curvature around the centre point of the front sections. 
     
     
       7. A link chain according to  claim 3 , wherein the fillet forms a transition via an intermediate circular portion into the hollow, wherein the radius of curvature of the intermediate circular portion is preferably less than half as large as the radius of curvature of the crowned fillet. 
     
     
       8. A link chain according to  claim 3 , wherein the hollow has a constant radius of curvature and the circular arc of the vertical chain links also has a constant radius which is preferably approximately 1 to 4 mm smaller than the radius of curvature of the hollow. 
     
     
       9. A link chain according to  claim 3 , wherein the hollow extends across an entire semi-circular portion into the longitudinal limbs. 
     
     
       10. A link chain according to  claim 1 , wherein the longitudinal limbs on the insides facing the inner opening are provided with a fillet which is cambered in a crowned manner, whose radius of curvature is preferably of equal size to the radius of curvature on the rear sides of the front sections. 
     
     
       11. A link chain, comprising:
 vertical chain links which have around the full circumference a constant cross-sectional profile provided on the inside with a circular arc and on the outside with a flat section; 
 horizontal chain links which have front sections with a straight face zone and longitudinal limbs, which connect the front sections around an oval inner opening and which are provided on their outer surfaces with a recess; 
 wherein the rear sides of the front sections delimiting the inner opening form a contact zone for the circular arcs of the vertical chain links, the horizontal chain links are provided on the rear sides, which face the oval inner opening, of the front sections with a surface which has a hollow, which forms a central region of the contact zone, within a fillet cambered in a crowned manner; and 
 wherein at least one horizontal chain link is provided on both sides in the recesses with an entrainment nose formed centrally between both front sections, each entrainment nose protruding in a projecting manner into the relevant recess. 
 
     
     
       12. A link chain according to  claim 11 , wherein each entrainment nose is formed on the longitudinal limb with a preferably trapezoidal cross-section. 
     
     
       13. A link chain according to  claim 12 , wherein the recesses have two linearly beveled flanks and a base section which is in a straight line up to the projecting entrainment nose, which is formed between the flanks. 
     
     
       14. A chain link, preferably for connection of entrainment scrapers to link chains for scraper chain conveyors for use in mining, comprising:
 front sections with a straight face zone and with longitudinal limbs, which connect the front sections around an oval inner opening and which are provided on their outer surfaces with a recess, 
 wherein the rear sides of the front sections delimiting the inner opening form a contact zone for circular arcs of vertical chain links and connect the longitudinal limbs to a semi-circular portion, the rear sides which face the oval inner opening of the front sections being provided with a surface which has a hollow, which forms a central region of the contact zone, between a fillet cambered in a crowned manner; and 
 wherein the chain link is provided on both sides in the recesses with an entrainment nose formed centrally between both front sections protrudes into the relevant recess. 
 
     
     
       15. A chain link according to  claim 14 , wherein the hollow extends with a constant radius of curvature across the surface of the rear sides of the front sections. 
     
     
       16. A chain link according to  claim 15 , wherein the radius of curvature of the hollow has a crown line which lies on a central longitudinal plane between the longitudinal limbs of the horizontal chain links. 
     
     
       17. A chain link according to  claim 16 , wherein the front sections have in the central longitudinal plane a circular cross-section with a radius which is preferably of equal size or substantially of equal size to the radius of curvature of the crowned fillet. 
     
     
       18. A chain link according to  claim 16 , wherein the crown line of the hollow forms a semicircle around the centre point of the front sections in the central longitudinal plane. 
     
     
       19. A chain link according to  claim 16 , wherein the hollow on the rear side of the front sections comprises a rotationally symmetrical unwinding of the radius of curvature around the centre point of the front sections. 
     
     
       20. A chain link according to  claim 16 , wherein the fillet forms a transition via an intermediate circular portion into the hollow, wherein the radius of curvature of the intermediate circular portion is preferably less than half as large as the radius of curvature of the crowned fillet. 
     
     
       21. A chain link according to  claim 16 , wherein the hollow has a constant radius of curvature and the circular arc of the vertical chain links also has a constant radius which is preferably approximately 1 to 4 mm smaller than the radius of curvature of the hollow. 
     
     
       22. A chain link according to  claim 16 , wherein the hollow extends across an entire semi-circular portion into the longitudinal limbs. 
     
     
       23. A chain link according to  claim 14 , wherein the longitudinal limbs on the insides facing the inner opening are provided with a fillet which is cambered in a crowned manner, whose radius of curvature is preferably of equal size to the radius of curvature on the rear sides of the front sections. 
     
     
       24. A chain link according to  claim 14 , wherein each entrainment nose is formed on the longitudinal limb with a preferably trapezoidal cross-section. 
     
     
       25. A chain link according to  claim 24 , wherein the recesses have two linearly beveled flanks and a base section which is in a straight line up to the projecting entrainment nose, which is formed between the flanks. 
     
     
       26. A link chain for chain conveyors, comprising:
 vertical chain links which have around the full circumference a constant cross-sectional profile provided on the inside with a circular arc and on the outside with a flat section; 
 horizontal chain links which have front sections with a straight face zone and longitudinal limbs, which connect the front sections around an oval inner opening and which are provided on their outer surfaces with a recess; 
 wherein the rear sides of the front sections delimiting the inner opening form a contact zone for the circular arcs of the vertical chain links, the horizontal chain links are provided on the rear sides, which face the oval inner opening, of the front sections with a surface which has a hollow, which forms a central region of the contact zone, within a fillet cambered in a crowned manner; 
 wherein the hollow extends with a constant radius of curvature across the surface of the rear sides of the front sections and the radius of curvature of the hollow has a crown line which lies on a central longitudinal plane between the longitudinal limbs of the horizontal chain links and the hollow on the rear side of the front sections comprises a rotationally symmetrical unwinding of the radius of curvature around the centre point of the front sections. 
 
     
     
       27. A link chain according to  claim 26 , wherein the fillet forms a transition via an intermediate circular portion into the hollow, wherein the radius of curvature of the intermediate circular portion is preferably less than half as large as the radius of curvature of the crowned fillet. 
     
     
       28. A link chain according to  claim 26 , wherein the hollow has a constant radius of curvature and the circular arc of the vertical chain links also has a constant radius which is preferably approximately 1 to 4 mm smaller than the radius of curvature of the hollow. 
     
     
       29. A link chain according  claim 26 , wherein the hollow extends across an entire semi-circular portion into the longitudinal limbs.